Air conditioning system



1944- -L. L ASPELIN ETAL AIR CONDITIONING SYSTEM Filed April 12, 1941 2 Sheets-Sheet 1 n a '1 all.

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AIR CONDITIONING SYSTEM Filed April 12, 1941 2 Sheets-Sheet 2 s 111mm operatively associated therewith a fan 2.

Patented Feb. 1. 1944 p AIR CONDITIONING SYSTEM Leslie L. Aspe'lin, Ewell 0. Phillips, and Ralph E.

Grey, Dayton, Ohio Application April 12, 1941, Serial No. 388,244

, dclaims. (01. 62129) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be mann factured and used by or for the Government for governmental purposes,without the payment to us of any royalty thereon.

This invention relates generally to a refrigerating or air conditioning system and more particularly to a novel combination of elements constituting a continuously operating system in which the rate of heat removal automatically responds to varying conditions.

It is an object of this invention to control the operation of a compressor in a'refrigerating unit in such a manner that its operation is responsive to the load requirements or output of the unit.

It is another object of this invention to control evaporator will maintain the compartment in Y which it is placed at a'predetermined temperature the operation of a compressor in a continuouslt operating refrigerating system in response to the capacity requirements of the system.

It is yet another object of this invention to eliminate the use of start-and-stop-compressordriving mechanisms as well as variable-speed devices used inconnection with compressor-driving mechanisms.

It is still another object of this invention to provide a compressor-driving and controlling mechanism which may be advantageously used in connection with several refrigerating units and a single condensing unit.

Figure 3 is a showing of a modification of the invention.

Referring to the drawings and particularly to Figure 1, there is shown an evaporator 1 having Connected to the evaporator by means oftubing 3 is a compressor 4 adapted to be driven by a suitable hydraulic drive 5, the operation and control of which is to be hereinafter more fully described. Connected to the compressor by tubing 1 is a condenser and receiver 8 for receiving and storing liquid refrigerant. The refrigerant is conveyed by'tubing 9 to the evaporator I through a suitable float valve or thermostatic expansion valve 10.

As is well known in mechanical refrigeration. the

under varying heat-exchange conditions. To maintain this balanced condition, the compressor is driven at a rate responsive to the condition of the refrigerant in the evaporator l.

The hydraulic drive for operating the com-.

pressor and the refrigerant-condition-responsive control for the drive will now be described: The fluid motor 5 comprising the hydraulic drive is operatively connected by a tubing l2 to pump 13 suitably drivingly'connected to prime mover I4 such as an airplane or vehicle engine. The pump I3 is connected by tubing l5 to a regulator l5 which controls the output-of the compressor by controlling the flow of driving fluid through the pump and the hydraulic drive. The regulator l6 includes a pressure-balanced valve l1 difierentially positioned by spring IBand bellows I9, the latter of which in turn is connected by tubing 20 at a suitable location to tubing 3. The tension in spring l8 may be adjusted by the spring-position.- ing-and-adjusting member 2| threaded into the body of regulator IS. The position of valve members l1 controlling the amount of fluid passing to the hydraulic drive is regulated by the force differential between spring [8 and the pressure, in bellows l9. This pressure is, as hereinbefore explained, responsive to the pressure of the refrigerant in the line 3 and consequently the evaporator l Thus an increase in suction pressure in the evaporator and suctionline resulting from a rise in temperature in the compartment in which compressor draws gaseous refrigerant from the evaporator I, compresses it and forces it into the condenser and receiver 8 from where it is conveyed by conduit 9 to the evaporator I where, by

the evaporator is placed will overcome the force .of the spring l8 to open valve I'I, allow more fluid to flow to the pump and hydraulic drive and cause the compressor to be driven at a higher rate. A reduction in pressure in bellows l9 brought about by a drop in temperature in the vicinity of the evaporator results in a relative closing'rnovement of valve l1 and an accompanying reduction in flow of driving fluid to the pump and motor. Valve I! may therefore be referred to as a metering valve.

operatively connected in return lines 22 and 24 is an expansion tank 23 which in turn is divided into two chambers by partition .25 having an opening 26 therein for establishing communication therebetween. A rod-gauge 21 is provided for determining the level of oil in tank 23 and the partition 25 is provided with a conical guiding portion 28 for guiding the gauge through the partition. The level of the liquid in the expansion chamber is above the partition at all times and at a level such that sufficient expansion space is provided within the chamber to accommodate surplus liquid when flow is restricted or stopped by valve [1.

. In the form of the invention illustrated in Figure 2, the valve is placed across a by-pass in the line between the pump and the hydraulic drive. Similarly to the form of invention as illustrated in Figure 1, the compressor 4a, condenser 8a, valve Illa and evaporator l a are operatively connected in series by tubing la, 90., and 3a. Compressor 4a is suitably connected to hydraulic drive 5a to be driven thereby. Hydraulic drive 5a is operatively connected, by tubing I20. and 24a, to pump |3a adapted to be driven by prime mover Ma.

The regulator Ifia for controlling the flow of driving fluid from pump I3a to hydraulic drive 50.

is connected--by means of tubing l5a and 22a to the pump I3a in parallel with the hydraulic drive 5a. The regulator lBa comprises a valve Ha operatively positioned by spring l8a and bellows I911. The interior of bellows I9a is connected by tubing 20a to line 3a connecting the evaporator and the compressor. A combined adstructure in Figure 1, the operation of the hydraulic drive for operating the compressor.

Although a single preferred embodiment of the invention has been described, it is to be understood that changes and modificationsmay be made in the device without departing from the spirit and substance of invention. Various modijusting screw and spring seat member 2Ia sion in spring 18a. is governed by the force differential between the .spring 3a and the force exerted by the bellows,

which in turn is dependent upon the condition of the refrigerant in the tubing 3a. Since the pressure in bellows 19a keeps valve Ila closed against the action of spring la, a decrease in refrigerant pressure in line So results in an opening of valve I'Ia and a consequent reduction of fluid flow from pump l3a to hydraulic drive 5a as a result of the by-pa'ss of fluid through the regulator. This results in a slowing down of the hydraulic drive 5a and compressor 4a and a reduction in the suctionpressure in 19a until the position of valve I'Ia is again changed.

In a modified form of the invention as illustrated in Figure 3, the pressure in the bellows l9a is controlled by a bulb 29 having high heat transferring qualities and containing a suitable fluid. The bulb is placed directly in the path of air blown through the evaporator l. The condition of the air blown through the evaporator lb affects the pressure of the fluid in the bulb 29 and consequently as described in connection with the fications and changes. may be made by those skilled in the art without departing from the inventive concept, and it is intended that the invention be limited only by the scope of the appended claims.

We claim:

1. In a refrigeration system including a compressor, a condenser and an evaporator, hydraulic means for continuously driving said compressor and means for controlling the rate of flow of fluid in the said hydraulic means to control the operation of the compressor in response to the pressure of the refrigerant in the evaporator including a balanced metering valve controlled by the pressure of the refrigerant leaving the evaporator.

2. In a refrigerating system includin a condenser, an evaporator and a compressor; hydraulic means for continuously driving said compressor, pump means for continuously operating said hydraulic means, and valve means directly responsive to the pressure of the refrigerant in the evaporator for regulating and controlling the effective operation of said pump, said valve means being operatively connected to said pump means in parallel with said hydraulic means.

3. In a refrigerating system including a condenser, an evaporator and a compressor, hydraulic means for continuously driving said compressor including a pump operatively connected.

thereto, and means operatively connected with said pump in parallel with said hydraulic driving means and directly responsive to the pressure of the refrigerant in the evaporator. for controlling the operation of the hydraulic-driving means to maintain a balanced condition in the refrigerating system.

4. A device as recited in claim 3, in which said control means includes a. valve, a spring for urging said valve into open position and a bellows operatively connected to a connection between the evaporator and the compressor and responsive to the pressure therein for urging said valve into closed position.

LESLIE L. ASPELIN. EWELL C. PHILLIPS. RALPH E. GREY. 

